I applied online, passed the online test, and was contacted for the position a month after. After a week, I was told they decided not to move on with me as a candidate.

This is all on the HCSS website. Passing the math test is the first step. Once you've done this, you'll receive an email response indicating whether or not they move forward. Next stage will be a phone interview. They will reach back in the next couple of days to update you on your status. If moving forward you will be invited onsite for an onsite math test (to confirm you know your stuff) and then 3 people who would be on your potential team will interview you. If they all say yes, you will be contacted by your recruiter for final round interviews with 2 executives and the CEO of the company.